A switching regulator represents a primary category for power converters design. Switching regulators are usually efficient, low cost and dissipate little heat. Due to the internal switching action, they tend to generate noise, which may be an issue in some applications. To reduce such switching induced noise, some designs have adopted a modulated clock frequency, such as triangle or spread spectrum frequency modulation, to vary the switching frequency from cycle to cycle. However, such frequency modulation can lead to increased noise in the output for the modulating frequency.